270 | Scientific Intelligence. 
The latter is however characteristic of the middle chalk, crate chlo- 
ritée, as also of the gault. In the middle of the chie f Cordillera of 
‘in 
which M. von Humboldt Gent brought it tous. ‘The or anic remains 
nelosed in the strata of these mountains of Santa Fe de Bogota prove 
_ Most decidedly the occurrence of the middle chalk, as I have endeavor- 
dto show in the description of Humboldt’s collection of American 
fully proved in his-no less instructive than masterly work on M. Bous- 
singault’s collections. But as the cretaceous formations in New Grenada 
atiain a thickness of, more. than 5000 feet, it is not surprising that the 
“from Socorra, whichis not distinct from the Exogyra Couloni of the 
pocomien any specimens of this same Exogyra were collected by 
“the late Er. Meyen on the declivities of the volcano of Maype in Chili 
“at the height of 13 ,000 feety and: (badly) figured.* Darwin alsot found 
it on the Portillo Pass in.the Peukenes chain, not far from Maypo, but 
also sixty English miles further north on the Uspalata Pass The Ea- 
~0Byra Coulont or aquila is, however, a true and very decided charac- 
“ale Coquimbo i in northern cule’ and those which Dom eyko, Professor 
Mineralogy in Coquimbo, has sent to Paris, again belong to newer 
, and are found in part also at a distance from It be- 
Pod ae ae: knot of transition beds which, along with older rocks, 
oi ve intruded: into the chain of the Andes.t ‘The most remarkable of 
tM ihees forms is the beautiful oe which Humboldt first brought 
_< © from San Felipe in the south of Quito, near the Amazon river, a 
which was figured and described by me a s PLEUROTOMARIA HumBoLD 
. in the ‘ Petrifactions,’ v. f, 26, first published ia in 1839. D’Orbignys 
ad 
“we rectly is still very doubtful. It appears, peculiarly characteristic ¢ of i 
ound it in ? 
whole southern districts of America. Darwin 
vance in the strata of Coquimbo, on the Rio Claro and near nates, 
‘and in like manner above Guasco and near Las Amolanos in the rrith 
goat valley, of f Conipg: | eae Pheerolomarye is always conjoined wat 
1 Acad vol. xvii, yi ii, vP b4a, t, MM, £5, 
: outh® han 
ss aie i 
a * % followed by Darwin, names it “ Turritella Andii,” but whether cor . 
